CASSELTON, N.D. (AP) -- A southeastern North Dakota town narrowly escaped tragedy when a train carrying crude oil derailed and exploded nearby, the mayor said Tuesday, calling for changes in how the fuel is transported across the U.S.

No one was hurt in Monday's derailment of the mile-long train that sent a great fireball and plumes of black smoke skyward about a mile from the small town of Casselton. The fire had been so intense as darkness fell that investigators couldn't get close enough to count the number of burning cars. The National Transportation Safety Board was preparing to investigate.